1. Field of the Invention
The present invention relates generally to specialized tools for use in the trucking industry, and more specifically to a collapsible tool for releasing the jaws retaining the kingpin in a fifth wheel assembly of a truck tractor. The present tool comprises a folding lever which may be braced across the rear tires of the tractor and overlying front portion of the trailer, to assist the user in releasing a stubborn or difficult to release fifth wheel release jaw.
2. Description of the Related Art
Heavy trucks used in the over the road trucking industry, have been standardized to a great extent over the years. Basically, such trucks comprise a tractor with driver's cab, engine, controls, etc., and a drive wheel system of from one to two axles and four to eight wheels. A so-called “fifth wheel” is positioned generally above the drive wheels for removable attachment of the king pin hitch of a semitrailer thereto, with a release handle being provided at the fifth wheel. The front end of such a semitrailer is supported by the drive wheels of the truck tractor, when the trailer is connected thereto.
It will be appreciated that the front end of a semitrailer may weigh on the order of twenty tons, depending upon the total load being carried and the weight distribution in or on the trailer. Accordingly, the force required to pull the fifth wheel release handle in order to release the hitch jaws from the trailer hitch king pin can be extremely high, depending upon any binding or high friction in the release system, and/or any misalignment between the truck tractor and the trailer, etc. Moreover, the hitch release handle is nearly universally positioned adjacent the frame of the tractor and inboard of the drive wheels, where it is not easily accessible. The awkward reach to access the release handle makes it even more difficult to gain leverage to overcome any resistance to its release.
As a result, a number of specialized fifth wheel jaw release tools, and combination tools comprising a fifth wheel release handle puller and other functions, have been developed in the past. Most such devices comprise a relatively simple bar or rod with a hook at one end, with the hook being secured to the fifth wheel release handle and the rod pulled to release the fifth wheel jaws. Some such devices comprise only a chain with a hook on the end for hooking to the release handle. Such devices provide no leverage for the user of the tool, and require an equal amount of force from the user as is required to pull the fifth wheel release handle directly. The amount of force required might at times be prohibitive, as noted further above, particularly for a person of lighter body build and/or suffering from some physical infirmity which prevents him or her from producing full strength.
This need has been recognized by a number of people, and has resulted in the development of various lever type tools to accomplish the release of a fifth wheel hitch connection between a truck tractor and semitrailer. However, all of the various devices of which the present inventor is aware, suffer from one or more defects which render them less than optimally suited for such work. Many do not fold compactly for storage in the limited space available in a truck tractor cab, while others fail to provide the adjustment needed for use with different truck tractors and trailers.
Accordingly, a need will be seen for a compactly folding fifth wheel release tool, which also provides the leverage often required to release the fifth wheel jaws of a tractor and trailer assembly. The present tool is also adjustable, in order to accommodate different dimensions between the outside of the tractor wheels and the side of the trailer, and the fifth wheel jaw release handle. A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 4,251,089 issued on Feb. 17, 1981 to Michael G. Skaggs, titled “Tractor-Trailer Vehicle Decoupling Tool,” describes a second class lever type fifth wheel release tool, in which the release handle attachment linkage comprises two rods, with the distal rod being pivotally secured to the lever attachment rod between the handle end and the fulcrum. The pivoting rod pair provides some folding for storage for the Skaggs device, but the handle of the Skaggs tool does not fold or telescope for greater leverage, as is the case with the present tool. Moreover, the pivoting pull rod assembly of the Skaggs tool does not provide any adjustment, whereas the present tool is adjustable for different reaches between the side of the vehicle assembly and the release handle.
U.S. Pat. No. 4,778,181 issued on Oct. 18, 1988 to James L. Arney, titled “Hand Tool For Truck Drivers And Policemen,” describes two separate tools, with one tool comprising an elongate telescoping rod having a hollow core capable of dispensing tear gas or the like. The Arney tool of interest herein, also comprises a telescoping rod with a hollow core. However, the Arney tool of interest includes a fifth wheel release hook which retracts to a substantially coaxial position with the telescoping extension for storage therein when the extension is retracted. The device described by Arney does not provide any leverage for the user; release force can only be applied in a purely linear direction, straight out from the fifth wheel release handle.
U.S. Pat. No. 4,871,182 issued on Oct. 3, 1989 to Russell G. Altherr et al., titled “Fifth Wheel Unlocking And Safety Latch Device,” describes a fifth wheel assembly including an integral release handle and mechanism. No separate, portable release handle manipulating tool is disclosed, nor is any telescoping or folding means provided for the permanently installed release handle of the Altherr et al. fifth wheel assembly.
U.S. Pat. No. 4,991,893 issued on Feb. 12, 1991 to Russell B. Gordon et al., titled “Manhole Cover Lifting Device,” describes a second class lever, i.e. a lever having a fulcrum at one end thereof with the applied force at the opposite end acting in the same direction as the resultant force therebetween. The present tool is also a second class lever, but differs from the Gordon et al. lever in that Gordon et al. fail to provide any telescoping or folding mechanism for their handle portion, and also fail to provide any length adjustment for the chain which applies the tensile force. Moreover, the relatively sharp fulcrum elements are unsuited for use against the side of a truck tire or trailer.
U.S. Pat. No. 5,344,201 issued on Sep. 6, 1994 to A. Dean Offin, titled “Multi-Function Tool For Truck Operators,” describes a generally L-shaped tool having a short handle end normal to an elongate pull rod portion. A fifth wheel release handle hook is provided at the end of the pull rod opposite the handle. No folding or telescoping is provided in the Offin tool, nor is any form of leverage or mechanical advantage provided by Offin.
U.S. Pat. No. 5,378,007 issued on Jan. 3, 1995 to Ronald W. Joyce, titled “Trailer Hitch Uncoupling Apparatus And Method Of Use,” describes a combination tool which may be used for releasing the fifth wheel of a tractor-trailer assembly, as well as for releasing the lock pin(s) for adjusting the position of the rear trailer wheels. The Joyce device is a first class lever when used to release the fifth wheel, i.e., the fulcrum is between the force applied by the user and the resultant force applied to the fifth wheel release, with the applied and resultant forces being in opposite directions. This results in the user having to push toward the truck and trailer assembly, rather than pulling away from the assembly as when the present tool is used. The need to push toward the vehicle to apply a pulling force on the release handle is not intuitive, and can be potentially hazardous if the release is stuck and then suddenly releases, with the user being suddenly propelled toward the side of the vehicle when the resisting force is released. Also, the element between the lever arm and the fifth wheel is rigid, although length adjustment is provided by means of a series of lever attachment holes therein. The rigid pulling element, along with the lack of folding of the lever arm, result in a somewhat bulkier tool than the tool of the present invention.
U.S. Pat. No. 5,423,567 issued on Jun. 13, 1995 to Bobby R. Upton, titled “Tractor Trailer Fifth Wheel Lever/Cable Assembly,” describes three different embodiments of a fifth wheel release tool. Each of the embodiments comprises a second class lever, as in the present fifth wheel release tool. However, none of the Upton devices provide a collapsible lever arm or tension member having an adjustable length, as provided by the present tool.
U.S. Pat. No. 5,803,518 issued on Sep. 8, 1998 to Brian S. Gibbons, titled “Tandem Axle Trailer Pin Leverage Handle System,” describes a second class lever tool intended for releasing the tandem axle lock pin at the rear of a semitrailer. The Gibbons tool includes a single piece handle incapable of being folded or collapsed, with a rigid rod having a fixed length being pivotally secured to the handle. While the Gibbons device might be capable of use as a fifth wheel handle release tool, the lack of folding for the handle and lack of length adjustment for the pull rod, result in a device unlike the present invention.
U.S. Pat. No. 5,863,060 issued on Jan. 26, 1999 to William E. Hollis et al., titled “Fifth Wheel King Pin Release Mechanism,” describes a permanently mounted second class lever for releasing the fifth wheel latch mechanism. Hollis et al. provide a lever pivotally attached at one end to the fifth wheel, with a tensile member extending from a point between the pivotal attachment and the opposite handle end. While Hollis et al. provide an adjustable extension for the handle, they do not provide any means of removing the device from its essentially permanent installation for storage.
U.S. Pat. No. 5,988,666 issued on Nov. 23, 1999 to James H. Flater, titled “Fifth Wheel Hitch Release,” describes a fifth wheel assembly having an integrated release mechanism therewith. Flater provides only a relatively short release handle with his fifth wheel mechanism, and does not provide any form of removable, collapsible or folding portable lever tool to assist in the release of the hitch mechanism.
U.S. Pat. No. 6,092,825 issued on Jul. 25, 2000 to James H. Flater, titled “Flatbar Fifth Wheel Release Handle,” describes a mechanism closely related to that of the '666 U.S. Patent to the same inventor, discussed immediately above. The same points of difference between that device and the present invention noted in the above discussion, are seen to apply here as well.
U.S. Pat. No. 6,354,642 issued on Mar. 12, 2002 to Scotty E. Haggerty, titled “Puller And Locator For Trailer Tandem Axle Units,” describes a combination tool having a telescoping length. The telescoping portion of the tool is used to apply tension adjustably to a spring, which is hooked to the axle assembly lock pin. A fifth wheel release hook is provided on the non-telescoping portion of the device opposite the handle, but no length adjustment or lever means is provided in the Haggerty combination tool.
U.S. Pat. No. D-377,924 issued on Feb. 11, 1997 to Greg A. Christensen, titled “Fifth Wheel Release Bar,” illustrates a design apparently serving as a second class lever. However, no folding or collapsing of the handle portion is apparent, nor is any length adjustment for the pulling element apparent in the Christensen design.
British Patent Publication No. 1,407,084 published on Sep. 24, 1975, titled “A Fifth Wheel Coupler,” describes a fifth wheel mechanism having a permanently installed release handle. No removably installable, portable release tool or lever means is disclosed in the '084 British Patent Publication.
Finally, British Patent Publication No. 2,160,163 published on Dec. 18, 1985, titled “Fifth-Wheel Trailer Coupling,” describes another fifth wheel mechanism with a permanently installed release handle. As in the '084 British Patent Publication discussed immediately above, no removably installable, portable release tool or lever means is disclosed in the '163 British Patent Publication.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a fifth wheel release lever solving the aforementioned problems is desired.